User-Mode Driver User-Mode Driver Framework: Introduction Framework: Introduction And OverviewAnd Overview

Jeffrey CopelandJeffrey CopelandProgram ManagerProgram ManagerWindows Device Experience GroupWindows Device Experience GroupMicrosoft CorporationMicrosoft Corporation

IntroductionIntroduction

What this talk coversWhat this talk coversOverviewOverview

Future directionsFuture directions

Intended audienceIntended audience

Other sessions of interestOther sessions of interestFollowing talk on UMDF architectureFollowing talk on UMDF architecture

Tomorrow’s UMDF lab session and Q&ATomorrow’s UMDF lab session and Q&A

Why User Mode?Why User Mode?

High-quality drivers are difficult to writeHigh-quality drivers are difficult to writeCrash statistics prove thisCrash statistics prove this

User mode drivers are “safer”User mode drivers are “safer”

Some Windows driver models already live Some Windows driver models already live in user spacein user space

Printers, audio, imagingPrinters, audio, imaging

UMDF is the general purpose user UMDF is the general purpose user space modelspace model

A Quick Word About WDFA Quick Word About WDF

Windows Driver Foundation is the Windows Driver Foundation is the successor to WDMsuccessor to WDM

WDM is deprecatedWDM is deprecated

New Kernel Mode and User Mode driver New Kernel Mode and User Mode driver frameworks – KMDF and UMDFframeworks – KMDF and UMDF

These fit into the driver life cycleThese fit into the driver life cycleDriver kitDriver kit

Test toolsTest tools

Installation toolsInstallation tools

How To Expose A DeviceHow To Expose A Device

You can use a stand-alone application You can use a stand-alone application with a DLL to directly access the devicewith a DLL to directly access the device

Non-shared deviceNon-shared device

You can write a service to share You can write a service to share the devicethe device

You can write a driver to use normal I/OYou can write a driver to use normal I/ONot WDM – Old technologyNot WDM – Old technology

UMDF?UMDF?

KMDF?KMDF?

UMDF versus KMDFUMDF versus KMDF

When to use UMDFWhen to use UMDFProtocol buses – USB, 1394, IPProtocol buses – USB, 1394, IP

Software-only drivers – Filters, virtual portsSoftware-only drivers – Filters, virtual ports

You must use KMDF if you needYou must use KMDF if you needMore stringent timing requirementsMore stringent timing requirements

Hardware access – DMA, interruptsHardware access – DMA, interrupts

Kernel-mode clients or access to kernel dataKernel-mode clients or access to kernel data

Hybrid-model driversHybrid-model drivers

Where Can You Use UMDF?Where Can You Use UMDF?

Where Can You Use UMDF?Where Can You Use UMDF?

TodayTodayDevice classes: Device classes:

Cell phones, media players, cameras, other Cell phones, media players, cameras, other portable devicesportable devicesRFID, NFCRFID, NFCBiometric and other security devicesBiometric and other security devicesDevices which currently are accessed directly Devices which currently are accessed directly through applications or servicesthrough applications or services

Buses:Buses:USB USB –– through WinUSB I/O Target through WinUSB I/O TargetIP – sockets through WinSockIP – sockets through WinSockBluetooth – RFCOMM or WinSockBluetooth – RFCOMM or WinSockAny bus that provides user-mode accessAny bus that provides user-mode access

Where Can You Use UMDF? Where Can You Use UMDF?

Factors to consider todayFactors to consider todayCan the device use a UMDF class driver?Can the device use a UMDF class driver?

Can the driver access device over that bus?Can the driver access device over that bus?

Does the kernel need to access the device?Does the kernel need to access the device?

FutureFutureWorking with device teams to drive Working with device teams to drive availabilityavailability

Need Feedback to help set prioritiesNeed Feedback to help set priorities

UMDF DevelopersUMDF Developers

Existing driver developersExisting driver developersWho want to move drivers to user spaceWho want to move drivers to user space

Who already have the “driver mindset”Who already have the “driver mindset”

New driver developersNew driver developersComing from application developmentComing from application development

Who need to provide device supportWho need to provide device support

Who are learning new skillsWho are learning new skills

Anyone who wants toAnyone who wants toBuild a driver without a lot of development overheadBuild a driver without a lot of development overhead

Reduce the risks associated with traditional driversReduce the risks associated with traditional drivers

Stop causing blue screensStop causing blue screens

KernelProgrammers

UMDF DevelopersUMDF Developers

UMDF developers come from UMDF developers come from two directionstwo directions

The application programmer still needsThe application programmer still needsto understand something about low-level to understand something about low-level system facilitiessystem facilities

Application Programmers

UMDF StructureUMDF Structure

UMDF driverUMDF driverFramework loads driver Framework loads driver

Driver then creates structure andDriver then creates structure andspecifies callbacks and event handlersspecifies callbacks and event handlers

C++ and “COM-lite”C++ and “COM-lite”

For more details stay for the UMDF For more details stay for the UMDF technical talktechnical talk

UMDF StructureUMDF Structure

Device StackDevice Stack

Driver Manager

Host ProcessUserUser

KernelKernel

Framework

UM driverFramework

UM driver

Reflector

...

CoInstaller

Kernel Driver

Kernel Driver

PerformancePerformance

Test system: hyper-threaded 3.2Ghz P4, 1GBTest system: hyper-threaded 3.2Ghz P4, 1GBPerformance sample availablePerformance sample available

Null driverNull driverRaw throughput up to 4 gigabits/secRaw throughput up to 4 gigabits/sec

Buffer size “sweet spot” 64-128 KbBuffer size “sweet spot” 64-128 Kb

Win32 I/O target – USB hard driveWin32 I/O target – USB hard driveThroughput 170 megabits/secThroughput 170 megabits/sec

CPU usage 11%CPU usage 11%

UMDF can easily saturate a USB 2.0UMDF can easily saturate a USB 2.0bus’s maximum speed of 480 megabits/secbus’s maximum speed of 480 megabits/sec

No adverse performance impact in No adverse performance impact in existing UMDF driversexisting UMDF drivers

Why To Use UMDFWhy To Use UMDF

Single WDF model – Both KM and UMSingle WDF model – Both KM and UM

Quicker development timeQuicker development timePnP/Power boilerplate is encapsulatedPnP/Power boilerplate is encapsulated

Debugging in user mode is easier!Debugging in user mode is easier!

Crashes in testing don’t force a rebootCrashes in testing don’t force a reboot

Access to user-mode servicesAccess to user-mode services

Shallow learning curve for Shallow learning curve for application developersapplication developers

Why To Use UMDFWhy To Use UMDF

Improved stabilityImproved stabilityUM drivers are isolated from each otherUM drivers are isolated from each other

Kernel is isolated from UM driversKernel is isolated from UM drivers

A step toward general driver isolationA step toward general driver isolation

Increased securityIncreased securityCompromised driver can’t crash the systemCompromised driver can’t crash the system

But may still compromise device dataBut may still compromise device data

RecoverabilityRecoverabilityDriver can recover or be restarted afterDriver can recover or be restarted aftera crash without a blue screena crash without a blue screen

Why To Use UMDFWhy To Use UMDF

““Writing a UMDF driver is relatively easy Writing a UMDF driver is relatively easy once you get your hands around using once you get your hands around using COM-lite.  Perhaps best of all, when your COM-lite.  Perhaps best of all, when your driver crashes while you're debugging it, driver crashes while you're debugging it, the system stays running.” the system stays running.” – Mark – Mark CariddiCariddi, , OSR OSR –– The NT Insider The NT Insider

““Plug-and-play and power management Plug-and-play and power management are easier to use. Queues and I/O targets are easier to use. Queues and I/O targets are straight-forward, and they have what I are straight-forward, and they have what I needed already.” needed already.” –– Janet Schneider, Janet Schneider, Microsoft Storage TeamMicrosoft Storage Team

Why To Use UMDFWhy To Use UMDF

““UMDF allows me to focus on the functional UMDF allows me to focus on the functional implementation, rather than the intricaciesimplementation, rather than the intricaciesof driver development. The best part about of driver development. The best part about UMDF drivers is that a crash doesn't causeUMDF drivers is that a crash doesn't causea blue screen.”a blue screen.”– Dan Polivy, Microsoft SideShow developer– Dan Polivy, Microsoft SideShow developer

Smart Card As A Case StudySmart Card As A Case Study

Rewrite of an existing WDM driverRewrite of an existing WDM driverDeveloper had driver knowledge,Developer had driver knowledge,but not WDM or WDF experiencebut not WDM or WDF experience

2 months to come up to speed on2 months to come up to speed onWDF and the existing driverWDF and the existing driver

1½ months to re-implement the1½ months to re-implement thedriver in UMDFdriver in UMDF

Smart Card As A Case StudySmart Card As A Case Study

35% code reduction – measured in 35% code reduction – measured in source bytessource bytes

4000 lines of PnP code removed4000 lines of PnP code removed

Functionally identical driver with less code, Functionally identical driver with less code, higher robustness, more maintainabilityhigher robustness, more maintainability

Code now “feels simpler”Code now “feels simpler”

Results are similar to experience porting Results are similar to experience porting WDM network and modem drivers to KMDFWDM network and modem drivers to KMDF

Smart CardSmart Card

Janet SchneiderJanet SchneiderStorage Driver developerStorage Driver developerMicrosoftMicrosoft

SideShowSideShow

Dan PolivyDan PolivyMobile PC developerMobile PC developerMicrosoftMicrosoft

UMDF AvailabilityUMDF Availability

Beta UMDF availableBeta UMDF availableFor Windows Vista nowFor Windows Vista now

For Windows XP next weekFor Windows XP next week

As update to the Beta 2 Windows Driver KitAs update to the Beta 2 Windows Driver Kit

Available for Windows Server 2003 at Available for Windows Server 2003 at same time as release for Windows Server same time as release for Windows Server codenamed "Longhorn"codenamed "Longhorn"

UMDF In The FutureUMDF In The Future

New driver models will move to WDFNew driver models will move to WDF

New features in UMDFNew features in UMDFWe’re in post-Windows Vista planning nowWe’re in post-Windows Vista planning now

We need your feedbackWe need your feedback

Help us decideHelp us decide

Possible convergence on OS platformsPossible convergence on OS platformsWindows MobileWindows Mobile

ResourcesResources

Join the WDF Beta ProgramJoin the WDF Beta Programhttps://connect.microsoft.com/availableprograms.aspxhttps://connect.microsoft.com/availableprograms.aspx

Sign in with your Microsoft Passport, and join the WDK/WDF betaSign in with your Microsoft Passport, and join the WDK/WDF beta

Participate in the UMDF newsgroupParticipate in the UMDF newsgroupmicrosoft.beta.windows.driverfoundation.umdfmicrosoft.beta.windows.driverfoundation.umdf at at

betanews.microsoft.combetanews.microsoft.com

WHDC web siteWHDC web site

DevCon 2005 presentationsDevCon 2005 presentationshttp://www.microsoft.com/http://www.microsoft.com/whdc/driver/wdf/UMDF.mspxwhdc/driver/wdf/UMDF.mspx

Join us for the UMDF lab and Q&A WednesdayJoin us for the UMDF lab and Q&A WednesdayLab requires a Design Preview AgreementLab requires a Design Preview Agreement

Ask the Experts Tuesday eveningAsk the Experts Tuesday evening

Call To ActionCall To Action

Install the Windows Driver KitInstall the Windows Driver Kit

Try UMDF for your driver projectsTry UMDF for your driver projects

Send us feedback!Send us feedback!We want to know how to make the framework We want to know how to make the framework betterbetter

We want to know what features are We want to know what features are still missingstill missing

Respond to our surveyRespond to our survey

UMDFFDBK @ microsoft.comUMDFFDBK @ microsoft.com

© 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions,

it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.